The use of transepidermal water loss to measure and predict the irritation response to surfactants.

Synopsis The ability of baseline transepidermal water loss (TEWL) measurements to predict the response of healthy subjects to a standard soap chamber irritation insult was evaluated. Chambers containing surfactant solutions were applied to the forearms of normal volunteers for five consecutive days. TEWL was measured using a Servo Med Evaporimeter. TEWL measurements were made prior to the first application of the chambers and following the removal of the second set of chambers (the afternoon of Day 1). The correlation between the TEWL values obtained on Day 1 and the subjective evaluation of irritation resulting from the application of two different toilet soaps was statistically significant. This result indicates that damage to the skin is reflected by an increase in TEWL. Interestingly, there was also a statistically significant correlation between TEWL values obtained on the untreated skin at Time 0 and the five-day average irritation score for these two cleansing products. The results of this study indicate that a high baseline TEWL value may be predictive of a high susceptibility to soap irritation as measured by the chamber test. Le role des pertes en eau transepidermique pour mesurer et prevoir l'irritation due aux tensio-actifs.